/*******************************************************************************
 * Copyright 2006, 2017 Jerry Huxtable, Martin Davis
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.locationtech.proj4j.units;

import java.io.Serializable;
import java.text.NumberFormat;
import java.util.Objects;

public class Unit implements Serializable {

    static final long serialVersionUID = -6704954923429734628L;

    public final static int ANGLE_UNIT = 0;
    public final static int LENGTH_UNIT = 1;
    public final static int AREA_UNIT = 2;
    public final static int VOLUME_UNIT = 3;

    public String name, plural, abbreviation;
    public double value;
    public static final NumberFormat format;

    static {
        format = NumberFormat.getNumberInstance();
        format.setMaximumFractionDigits(2);
        format.setGroupingUsed(false);
    }

    public Unit(String name, String plural, String abbreviation, double value) {
        this.name = name;
        this.plural = plural;
        this.abbreviation = abbreviation;
        this.value = value;
    }

    public double toBase(double n) {
        return n * value;
    }

    public double fromBase(double n) {
        return n / value;
    }

    public double parse(String s) throws NumberFormatException {
        try {
            return format.parse(s).doubleValue();
        }
        catch (java.text.ParseException e) {
            throw new NumberFormatException(e.getMessage());
        }
    }

    public String format(double n) {
        return format.format(n)+" "+abbreviation;
    }

    public String format(double n, boolean abbrev) {
        if (abbrev)
            return format.format(n)+" "+abbreviation;
        return format.format(n);
    }

    public String format(double x, double y, boolean abbrev) {
        if (abbrev)
            return format.format(x)+"/"+format.format(y)+" "+abbreviation;
        return format.format(x)+"/"+format.format(y);
    }

    public String format(double x, double y) {
        return format(x, y, true);
    }

    public String toString() {
        return plural;
    }

    public boolean equals(Object o) {
        if (o instanceof Unit) {
            return ((Unit)o).name.equals(name) && ((Unit)o).value == value;
        }
        return false;
    }

    @Override
    public int hashCode() {
        return Objects.hash(this.getClass(), name, value);
    }
    
}
